Multi-Level Outlet Weir for Enhanced Volumetric Separation for Stormwater Treatment

ABSTRACT

A method, system, and apparatus directed to an innovative approach for the treatment of stormwater utilizing hydrodynamic separator assembly designed to maximize flow movement for more efficient sediment removal and maximize water flow control.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a non-provisional application of U.S. patentapplication Ser. No. 17/062,518 filed on Oct. 2, 2020, which was anonprovisional of U.S. Provisional Application No. 62/909,619, filedOct. 2, 2019 and a continuation in part of U.S. Nonprovisionalapplication Ser. No. 16/505,275 filed Jul. 8, 2019, now U.S. Pat. No.11,261,595 registered on Mar. 1, 2022, which is a continuation of U.S.patent application Ser. No. 15/700,149 filed Sep. 10, 2017, now U.S.Pat. No. 10,344,466 registered on Jul. 9, 2019.

FIELD OF THE INVENTION

The embodiments of the present technology relate in general enhancedpollutant removal of particulates for the application of stormwatertreatment.

The present invention provides a concept and method for providingenhanced pollutant removal for particulates for the application ofstormwater treatment. Said invention utilizes an innovative multi-levelorifice outlet flow control weir inside a box or manhole structure forremoval of sediments and other particulate pollutants.

Current stormwater separators use various internal components, such asbaffles, walls, round cylinders, down pipes, oil skimmers, and otherinternal mechanism to control the flow and or flow path of water thattravels through it in an attempt to maximize sediment removal. Somedevices have down pipes or up pipes within the internals that aim tocontrol the flow in a certain path to increase sediment removal. This isknown as water path maximization which allows for more time for finerparticulates to fall out of suspension.

While there are other various inventions taught in the prior art whichprovide the benefit of increasing performance of particulate removal,their inherent limitations are based on a simplistic flow control designusing a single flow path through the system for all flow rates or twoflow paths, one for treated flows and one for higher bypass flows. Noneof these systems aim to provide better control of water level atdifferent flows, and leveraging that increased water level to increasethe wet volume of the system and thus maximize volumetric separationover a range of flow rates to maximize overall performance.

Testing has proven that the same treatment system, with a multi-levelorifice control outlet weir provides a substantial increase inperformance over the system without the orifice control outlet weir (SeeFIGS. 13 and 14 ). This has been proven based independent testing done abaffle box system tested under the New Jersey Department ofEnvironmental Protection protocol for hydrodynamic separators.

BACKGROUND

Water treatment systems have been in existence for many years. Thesesystems treat stormwater surface runoff or other polluted water.Stormwater runoff is of concern for two main reasons: i. volume and flowrate, and ii. pollution and contamination. The volume and flow rate ofstormwater runoff is a concern because large volumes and high flow ratescan cause erosion and flooding. Pollution and contamination ofstormwater runoff is a concern because stormwater runoff flows into ourrivers, streams, lakes, wetlands, and/or oceans. Pollution andcontamination carried by stormwater runoff into such bodies of water canhave significant adverse effects on the health of ecosystems.

In the early 2000s the EPA and California Regional Water Quality Boardsissued what is known as a Total Maximum Daily Load for trash in the LosAngeles Region, specifically the Los Angeles River Watershed. Countlessstudies were done on the river and its discharge into the Pacific Ocean.It was found that the amount of trash entering the river basin from thestorm water infrastructure far exceeded any acceptable levels. Therewere several environmental groups advocating for action to be taken toreduce the amount of trash discharged into the river and otherwatersheds.

The Clean Water Act of 1972 enacted laws to improve water infrastructureand quality. Sources of water pollution have been divided into twocategories: point source and non-point source. Point sources includewastewater and industrial waste. Point sources are readily identifiable,and direct measures can be taken to mitigate them. Non-point sources aremore difficult to identify. Stormwater runoff is the major contributorto non-point source pollution. Studies have revealed that contaminatedstormwater runoff is the leading cause of pollution to our waterways. Aswe build houses, buildings, parking lots, roads, and other imperviousareas, we increase the amount of water that runs into our stormwaterconveyance systems and eventually flows into rivers, lakes, streams,wetlands, and/or oceans. As more land becomes impervious, less rainseeps into the ground, resulting in less groundwater recharge and highervelocity flows, which cause erosion and increased pollution levels ofwatery environments.

Numerous sources introduce pollutants into stormwater runoff Sedimentsfrom hillsides and other natural areas exposed during construction andother human activities are one source of such pollutants. When land isstripped of vegetation, stormwater runoff erodes the exposed land andcarries it into storm drains. Trash and other debris dropped on theground are also carried into storm drains by stormwater runoff Anothersource of pollutants is leaves and grass clippings from landscapingactivities that accumulate on hardscape areas and do not decompose backinto the ground, but flow into storm drains and collect in huge amountsin lakes and streams. These organic substances leach out large amountsof nutrients as they decompose and cause large algae blooms, whichdeplete dissolved oxygen levels in marine environments and result inexpansive marine dead zones. Unnatural stormwater polluting nutrientsinclude nitrogen, phosphorus, and ammonia that come from residential andagricultural fertilizers.

Heavy metals that come from numerous sources are harmful to fish,wildlife, and humans. Many of our waterways are no longer safe forswimming or fishing due to heavy metals introduced by stormwater runoff.Heavy metals include zinc, copper, lead, mercury, cadmium, and selenium.These metals come from vehicle tires and brake pads, paints, galvanizedroofs and fences, industrial activities, mining, recycling centers, etc.Hydrocarbons are also of concern and include oils, gas, and grease.These pollutants come from leaky vehicles and other heavy equipment thatuse hydraulic fluid, brake fluid, diesel, gasoline, motor oil, and otherhydrocarbon-based fluids. Bacteria and pesticides are additional harmfulpollutants carried into waterways by stormwater runoff.

Over the last 20 years, the Environmental Protection Agency (EPA) hasbeen monitoring the pollutant concentrations in most streams, rivers,and lakes in the United States. Over 50% of waterways in the UnitedStates are impaired by one of more of the above-mentioned pollutants. Aspart of the EPA Phase 1 and Phase 2 National Pollutant DischargeElimination Systems, permitting requirements intended to controlindustrial and nonindustrial development activities have beenimplemented. Phase 1 was initiated in 1997 and Phase 2 was initiated in2003. While there are many requirements for these permits, the mainrequirements focus on pollution source control, pollution control duringconstruction, and post construction pollution control. Post constructioncontrol mandates that any new land development or redevelopmentactivities incorporate methods and solutions that both control increasedflows of surface water runoff from the site and decrease (filter out)the concentration of pollutants off the site. These requirements arecommonly known as quantity and quality control. Another part of theserequirements is for existing publicly owned developed areas to retrofitthe existing drainage infrastructure with quality and quantity controlmethods and technologies that decrease the amount of surface waterrunoff and pollutant concentrations therein.

SUMMARY OF THE INVENTION

A hydrodynamic separation device for stormwater or other wastewatersprimarily utilizing the forces of gravity and buoyancy to removeparticulates from water flows within a an enclosed chamber having one ormore inlets and outlets on the sides, tops, or bottoms of the chamber.The device utilizing a unique and revolutionary approach of one or moreoutlet orifice controls to precisely control the water level anddischarge rate out of the system at various inlet flow ranges such asdry weather flow, low flow wet weather, medium flow wet weather, highflow wet weather and other conditions. This unique hydraulic approachallows the designers to decide and optimize the desired removalefficiencies of pollutants such as sediments at known flow ranges tobetter control the performance curve. General sediment removalperformance curves are mostly linear. The addition of multi-levelorifice controls on the outlet create a more tiered or terracedperformance curve therefore maintaining a higher performance levelthrough a wider ranges of flows. The orifice controls also enhance theincrease the general volume of water in the system to increase the wetvolume of water in the system which also further improves performancevia increased retention time. The combination of enhanced flow andvolume control lead to a better overall hydrodynamic separator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cut-away view of a preferred embodiment of a hydrodynamicseparation device clearly identifying different potential locations oforifices on outlet weirs.

FIG. 2 is a side view of a preferred embodiment of a hydrodynamicseparation device.

FIG. 3 is a cut-away end view of a preferred embodiment of ahydrodynamic separation device clearly identifying different potentiallocations of orifices on outlet weirs.

FIG. 4 is a bottom plan view of a preferred embodiment of a hydrodynamicseparation device.

FIG. 5 is a cut-away view of an alternative shape of a preferredembodiment of a hydrodynamic separation device.

FIG. 6 is a cut-away view of cut-away view a round manhole structure asa preferred embodiment of a hydrodynamic separation device.

FIG. 7 is a cut-away end view of a preferred embodiment of ahydrodynamic separation device clearly identifying different potentiallocations of orifices on outlet weirs.

FIG. 8 is a top plan view of round manhole structure as a hydrodynamicseparation device.

FIG. 9 is a cut-away view begins to illustrate how water flows throughthe hydrodynamic separation device during different conditions. In thiscase during dry weather flows.

FIG. 10 is a cut-away view of low water flows through the hydrodynamicseparation device.

FIG. 11 is a cut-away view of a cut-away view of peak treat water flowsthrough the hydrodynamic separation device.

FIG. 12 is a cut-away view of a cut-away view of high water flowsthrough the hydrodynamic separation device, resulting in a bypass.

FIG. 13 presents third-party test results of the performance of ahydrodynamic separation device without orifices versus the samehydrodynamic separation device with orifices on the weirs.

FIG. 14 presents third-party test results of the performance of ahydrodynamic separation device without orifices versus the samehydrodynamic separation device with orifices with greater detail in thedata measured.

DETAILED DESCRIPTION

After reading this description it will become apparent to one skilled inthe art how to implement the invention in various alternativeembodiments and alternative applications. However, all the variousembodiments of the present invention will not be described herein. It isunderstood that the embodiments presented here are presented by way ofan example only, and not limitation. As such, this detailed descriptionof various alternative embodiments should not be construed to limit thescope or breadth of the present invention as set forth below.

Hydrodynamic separators of various shapes utilize a permanent standingwater pool to settle and efficiently store captured sediments such astotal suspended solids deep enough so they are not scoured out. Allsystems require the water level to return to the invert of the outletpipe between storm events as water cannot be allowed to back up into theinlet pipe and submerge the drainage system upstream. Because of thisinherent design the size of the outlet pipe is generally the limitingpoint of flow restriction during high flows. During low flows it doesnothing to control the flow through the system and thus there is nodifference between the hydraulic grade line (water level) in andhydraulic grade line (water level) out. Therefore, the volume insidesystem (wet volume of water) is not increased at the lower flow rates.Therefore, performance is not maximized at these lower flow ratesbecause the volume increase is minimal.

The present invention utilizes a weir placed around the outlet pipe. Theinvention has at least one weir at the bottom that allows the waterlevel to drain back down to the invert of the outlet pipe after a rainevent. It also decreases the discharge rate for very low and dry weatherflows by backing the water level up behind the weir, increasing volume,slowing the discharge rate, which increase performance. The higher thevolume and the lower the loading rate (gpm/sq ft settling surface area)the better the particulate removal. With a single bottom orifice thevolume in the system is increased up to and above the peak treatmentflow rate as the HGL through the system is substantially higher than itwould be without (if only controlled by the size of the outlet pipe). Itshould be noted that the outlet pipe must be kept big to handle the peakbypass flow rate so using a smaller outlet pipe is not an option. Theorifice control weir allows a large pipe to be used while at the sametime backing up the water to increase volume, reduce loading rate, andincrease performance.

Additionally, one more or more orifices can be added on the side wall ofthe outlet control orifice weir to provide flow control and set HGLs atdifferent flow rates in a more linear fashion versus uncontrolleddischarge. The loading rate can be manipulated to stay lower for longerin proportion to the increase of volume. The volumetric loading rate iscontrolled as well and improves performance. Volumetric loading is thewet volume of water divided by the flow rate through the system. Testinghas shown that the volumetric loading rate is a more accurate in scalingperformance than surface area loading and thus the volumetric control ofthis weir concept with one or more orifices added to a box or roundstructure used for separation provides real benefit.

Flow control through the hydrodynamic separation chamber is important inorder to control target flow rates. Surface loading rate and hydraulicretention time are important variables that affect the performance ofthe chamber and its ability to remove pollutants. Specific retentiontimes are needed, specifically to allow for certain size particles tosettle out to the floor. Most similar systems known in the art areunable to perform at a designed target level of one fluctuations inwater levels and cannot control for the speed of which the water travelsthrough the system (as measured in gallons/minute, or gpm/sq ft). Thisis particularly true in periods of high flow and fill up and drain downperiods.

As described herein, flow control of the water traveling through thesystem solves for these problems with a combination of weirs andorifice(s) mounted before the outlet pipe.

In some embodiments, the orifices can be arranged in different positionson the weirs in order to control for the flow at different water levels.

The components of the hydrodynamic separation device can be comprised ofdifferent materials. As an example: the hydrodynamic separation devicemetal, plastic, concrete, fiberglass, composite, and a combinationthereof. Additionally, flow weirs may be selected from a groupconsisting of: non-corrosive materials including: metal, plastic,concrete, fiberglass, composite, and a combination thereof. Also, inletand outlet pipes may be selected from a group consisting of: metal,plastic, concrete, clay, or a combination thereof.

FIG. 1 begins to illustrate the elements of a preferred embodiment ofthe invention via a cut-away view, demonstrating the box structure 10,inlet pipe 1, the end of the wall box 4, the bottom of the box 6, thetop of box 3, and the side wall of the box 5. The outlet end of the box10 includes a horizontal outlet orifice 8, providing flow controlthroughout the box system 10. The outlet orifice 8 is located on theoutlet flow control weir 7 which is connected to the exiting hole of theoutlet pipe 2.

FIG. 2 illustrates a side view of a preferred embodiment of the boxstructure 10 with the inlet pipe 1 on the left side of this view and theoutlet pipe 2. The walls of the box structure includes the top of box 3,the end of the wall box 4, and bottom of the box 6, and access openings11. Aligned internally to the outlet pipe 2 are the components of theoutlet flow control weir 7 with outlet orifices 8, the vertical outletorifice 9.

FIG. 3 illustrates a cutaway, end view of the box structure 10highlighting the outlet flow control weir 7 with horizontal outletorifices 8 attached to the outlet pipe 2. Also depicted is an accessopening 11 on the top of box 3 of the box structure 10. The boxstructure 10 has side walls of the box 5 and the bottom of the box 6.

FIG. 4 presents the box structure 10 with the ends of the wall box 4,the bottom of the box 6, the side walls of the box 5, inlet pipe 1 andthe outlet pipe 2. Also show is the outlet flow control weir 7, anoutlet orifice 8, and a vertical outlet orifice 9.

FIG. 5 presents an alternative embodiment of the outlet orifices 8 withmultiple orifices. Adding one or more orifices to the outlet orifices 9provides increases flow control to better maintain the target loadingrate during different stages of water levels within the box structure10, or as seen in this figure, the round manhole structure 20. Alsodepicted in FIG. 5 are the side wall of round manhole structure 14, thebottom of round manhole structure 16, an outlet flow control weir for around structure 17, and wall mounts with vertical side flanges 22. Aswith the box structure 10, there is an inlet pipe 1 and the outlet pipe2.

FIG. 6 presents a cutaway view of the round manhole structure 20 withbottom of round manhole structure 16, side walls of round manholestructure 14, an inlet pipe 1, the outlet pipe 2, and the top of manholestructure 13 with access openings 11. As presented as a preferredembodiment are the outlet flow control weir for a round structure 17with multiple outlet orifices 8 and a vertical outlet orifice 9. Thewall mount horizontal flange 23 separates the outlet flow control weirfor a round structure 17 from the outlet pipe 2.

FIG. 7 isolates the outlet flow control weir for a round structure 17with multiple outlet orifices 8 and the wall mount horizontal flange 23.Also shown is the top of manhole structure 13 with access openings 11,the side walls of round manhole structure 14 and bottom of round manholestructure 16.

FIG. 8 is a top view of the round manhole structure 20 with side wallsof round manhole structure 14 and bottom of round manhole structure 16.Water enters the system through an inlet pipe 1 and exits via the outletpipe 2. Alternative embodiments may include more than one inlet pipe 1and/or the outlet pipe 2. The outlet flow control weir for a roundstructure 17 and vertical outlet orifices 9 with outlet orifice 8 andwall mounts with vertical side flanges 22 are located just within theoutlet pipe 2.

FIG. 9 begins to show how water flows through the system and the valueof outlet orifices 8. During periods of dry weather flows, water entersthe round manhole structure 20, or alternately a box structure 10 (notshown) during a dry weather flow event 30 via the inlet pipe 1, or otherinlet opening such as an access opening 11 (not shown). Within thisfigure of a round manhole structure 20 with side walls of round manholestructure 14 and bottom of round manhole structure 16. Also depicted isthe outlet flow control weir for a round structure 17, with a horizontaloutlet with multi-level orifices 8 and a vertical outlet orifice 9attached to an outlet pipe 2.

FIG. 10 presents a similar scenario; however, with low flow movement ofwater levels 31. Water enters the round manhole structure 20 via theinlet pipe 1, or other inlet opening such as an access opening 11 (notshown). Within this figure of a round manhole structure 20 with sidewalls of round manhole structure 14 and bottom of round manholestructure 16. Also depicted is the outlet flow control weir for a roundstructure 17, with a horizontal outlet with multi-level orifices 8 and avertical outlet orifice 9 attached to an outlet pipe 2.

FIG. 11 presents an alternate scenario where the system processes a peaktreatment flow water level 32. Within this figure of a round manholestructure 20 with side walls of round manhole structure 14 and bottom ofround manhole structure 16. Also depicted is the outlet flow controlweir for a round structure 17, with a horizontal outlet with multi-levelorifices 8 and a vertical outlet orifice 9 attached to an outlet pipe 2.

FIG. 12 presents an alternate scenario where the system processesincoming water during high flows which incorporates a bypass flow waterlevel 33. Within this figure of a round manhole structure 20 with sidewalls of round manhole structure 14 and bottom of round manholestructure 16. Also depicted is the outlet flow control weir for a roundstructure 17, with a horizontal outlet with multi-level orifices 8 and avertical outlet orifice 9 attached to an outlet pipe 2.

FIG. 13 presents third-party test results of the performance of thecomparison of the same type of hydrodynamic separation device with noorifices controlling the loading flow rate 40 in comparison to weir andorifice-controlled loading flow rate 41. The weir and orifice-controlledloading flow rate 41 meets optimal loading rates during different waterlevel scenarios.

FIG. 14 presents third-party test results of the performance furtherdetailing the performance of a hydrodynamic separation device without anorifice control outlet weir versus a hydrodynamic separation device withan orifice control outlet weir versus. Performance is measured comparingHGL about the outlet pipe invert (measured in feet (ft)), the wet volume(cu feet) and the loading rate (gpm/cu ft).

I/We claim:
 1. A hydrodynamic separator assembly configured forinstallation within a stormwater drainage infrastructure, wherein thehydrodynamic separator has substantially circular walls with a top, withone or more access openings, a bottom, at least one inlet opening and atleast one outlet opening; wherein said hydrodynamic separator, containsan outlet weir, said outlet weir with weir shelves and wall is attachedto said wall of hydrodynamic separator via mounts, and positioned sothat the wall of the outlet weir is disposed across the outlet openinghorizontally level; wherein the outlet weir has two or more orificesarranged in a vertical orientation, including one or more orifices onthe shelf portion of the outlet weir to control water level anddischarge rate at low flow conditions, one or more orifices on the wallportion of the outlet control weir to control water level and dischargerate at moderate flow conditions, and the top of the outlet weir set ata higher elevation than the orifices to control the water level athigher flows that exceed the flow capacity of the multiple orificesbelow; wherein the level and size of each orifice is set and designedbased upon hydraulic calculations that optimize the overall performancecurve for removal of particulate pollutants over all flow ranges byincreasing the volume of water to a higher level during lower flowconditions and therefore decreasing gallons per minute per cubic foot ofwet volume and increasing performance.
 2. The hydrodynamic separatorassembly of claim 1, wherein the outlet weir is configured to provide anelongated horizontal plane diversion for treated stormwater to flow overthe top; wherein the outlet weir is comprised of a wall with two sidemounts, where the side mounts extend the length of the wall; wherein thewall and side mounts connect seamlessly to a curved weir shelf; whereinsaid curved weir shelf has one or more outlet weir orifice controlholes; wherein the outlet weir assembly of wall, side mounts, shelf, andorifice control holes are affixed to a curved bottom mount configured tobe flush with the invert curve of the inside of the sump chamber belowthe bottom of an outlet pipe.
 3. The hydrodynamic separator assembly ofclaim 1, wherein casing of the assembly is selected from the groupconsisting of: metal, plastic, concrete, fiberglass, composite, and acombination thereof.
 4. The hydrodynamic separator assembly of claim 1,wherein the flow weirs are selected from a group consisting of:non-corrosive materials including: metal, plastic, concrete, fiberglass,composite, and a combination thereof.
 5. The hydrodynamic separatorassembly of claim 1, wherein the inlet and outlet pipes are selectedfrom a group consisting of: metal, plastic, concrete, clay, or acombination thereof.
 6. The hydrodynamic separator assembly of claim 1,wherein the overall size of the system has a diameter of 2 feet to 100feet.
 7. The hydrodynamic separator assembly of claim 1, wherein theinlet and outlet pipes have a diameter of 2 inches to 30 feet.
 8. Ahydrodynamic separator assembly configured for installation within astormwater drainage infrastructure, wherein the hydrodynamic separatorhas four side walls, a top, with one or more access openings, a bottom,at least one inlet opening and at least one outlet opening; wherein saidhydrodynamic separator, contains an outlet weir, said outlet weir withweir shelves and wall is attached to said wall of hydrodynamic separatorvia mounts, and positioned so that the wall of the outlet weir isdisposed across the outlet opening horizontally level; wherein theoutlet weir has two or more orifices arranged in a vertical orientation,including one or more orifices on the shelf portion of the outlet weirto control water level and discharge rate at low flow conditions, one ormore orifices on the wall portion of the outlet control weir to controlwater level and discharge rate at moderate flow conditions, and the topof the outlet weir set at a higher elevation than the orifices tocontrol the water level at higher flows that exceed the flow capacity ofthe multiple orifices below; wherein the level and size of each orificeis set and designed based upon hydraulic calculations that optimize theoverall performance curve for removal of particulate pollutants over allflow ranges by increasing the volume of water to a higher level duringlower flow conditions and therefore decreasing gallons per minute percubic foot of wet volume and increasing performance.
 9. The hydrodynamicseparator assembly of claim 8, wherein the outlet weir is configured toprovide an elongated horizontal plane diversion for treated stormwaterto flow over the top; wherein the outlet weir is comprised of a wallwith two side mounts, where the side mounts extend the length of thewall; wherein the wall and side mounts connect seamlessly to a weirshelf; wherein said weir shelf has one or more outlet weir orificecontrol holes; wherein the outlet weir assembly of wall, side mounts,shelf, and orifice control holes are affixed to a bottom mountconfigured to be flush with the invert of the inside of the sump chamberbelow the bottom of an outlet pipe.
 10. The hydrodynamic separatorassembly of claim 8, wherein casing of the assembly is selected from thegroup consisting of: metal, plastic, concrete, fiberglass, composite,and a combination thereof.
 11. The hydrodynamic separator assembly ofclaim 8, wherein the flow weirs are selected from a group consisting of:non-corrosive materials including: metal, plastic, concrete, fiberglass,composite, and a combination thereof.
 12. The hydrodynamic separatorassembly of claim 8, wherein the inlet and outlet pipes are selectedfrom a group consisting of: metal, plastic, concrete, clay, or acombination thereof.
 13. The hydrodynamic separator assembly of claim 8,wherein the overall size of the system has a diameter of 2 feet to 100feet.
 14. The hydrodynamic separator assembly of claim 8, wherein theinlet and outlet pipes have a diameter of 2 inches to 30 feet.